The Guerezas, which represent the Langurs in Asia, inhabit {87}Tropical Africa, ranging from Abyssinia and Zanzibar in the east, to Senegambia, Angola, and perhaps the island of Fernando Po on the west--between about 15° N. lat. on the eastern and 12° on the western side, to 10° S. lat. They live in small troops in the forest, both on the plains and on the mountains, their food consisting of fruits, but principally of leaves, which they eat in large quantities, as the peculiar and capacious form of their storehouse-like stomach, in lieu of cheek-pouches, would indicate. Of their habits in their native state very little indeed is known, for they prefer to keep to the great trees of the forests far from human habitation; while, owing to their very delicate constitution enabling them to resist for a very short period the rigours of a climate cooler than their own, scarcely anything has been learnt of them in captivity. The beautiful skins of many of the species form a considerable article of commerce in Europe and America to adorn the costumes of the most refined and cultivated ladies, who vie for their possession with the semi-nude and barbarous warriors of Equatorial Africa, by whom they are also used as ornaments for their persons and for decorations for their weapons. I. VAN BENEDEN'S GUEREZA. COLOBUS VERUS. _Colobus verus_, Van Bened., Bull. Acad. Sc., Brux., v., p. 344, pl. 13 (1838); Less., Spec. Mamm., p. 70 (1840); Martin, Mammif. Anim., p. 503 (1841); Geoffr., Cat. Méth. Primates, p. 17, no. 4 (1851); Wagner, in Schreber, Säugeth. Suppl., v., p. 37 (1855); Gray, P. Z. S., 1868, p. 182; Schl. Mus. Pays-Bas, vii., p. 28 (1876). _Semnopithecus_ (_Colobus_) _olivaceus_, Wagner, in Schreber's Säugeth. Suppl., i., p. 309 (1840). {88}_Colobus cristatus_, Gray, Ann. and Mag. N. H. (3), xvii., p. 77 (1866); id., P. Z. S., 1886, p. 182, pl. xv.; id., Cat. Monkeys Brit. Mus., p. 19, et Suppl., p. 128 (1870). _Procolobus verus_, Rochebr., Faun. Sénég., Mamm. Suppl., p. 97, pl. 1 (1887). CHARACTERS.--Body stout; limbs robust; head oval, the muzzle slightly prominent; face and ears naked, brownish-black; thumb entirely absent; callosities large. Hair on the top of the head, forming a median crest, reddish-olive; whiskers, directed backward, pale yellow; over the eyes a frontal bar of the same colour, coalescing with the whiskers opposite the eyes; upper part of body to base of tail and down to the knees, covered with short dark olive-brown hair, finely ringed with black, and washed with rufous on the back of the neck and on the outside of the thighs; the tail long and thin, olive-brown or brownish-grey; shoulders, flanks, and outer surface of the limbs, pale greyish-green; upper sides of the hands and feet reddish-brown; throat, chest (the hair of which is elongated), under surface of the body and inner side of the limbs, ashy-grey. Length of body, 21 inches; of tail, 24¼.